Merge tag 'pci-v5.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull pci updates from Bjorn Helgaas:
 "Enumeration:
   - Conserve IRQs by setting up portdrv IRQs only when there are users
     (Jan Kiszka)
   - Rework and simplify _OSC negotiation for control of PCIe features
     (Joerg Roedel)
   - Remove struct pci_dev.driver pointer since it's redundant with the
     struct device.driver pointer (Uwe Kleine-König)

  Resource management:
   - Coalesce contiguous host bridge apertures from _CRS to accommodate
     BARs that cover more than one aperture (Kai-Heng Feng)

  Sysfs:
   - Check CAP_SYS_ADMIN before parsing user input (Krzysztof
     Wilczyński)
   - Return -EINVAL consistently from "store" functions (Krzysztof
     Wilczyński)
   - Use sysfs_emit() in endpoint "show" functions to avoid buffer
     overruns (Kunihiko Hayashi)

  PCIe native device hotplug:
   - Ignore Link Down/Up caused by resets during error recovery so
     endpoint drivers can remain bound to the device (Lukas Wunner)

  Virtualization:
   - Avoid bus resets on Atheros QCA6174, where they hang the device
     (Ingmar Klein)
   - Work around Pericom PI7C9X2G switch packet drop erratum by using
     store and forward mode instead of cut-through (Nathan Rossi)
   - Avoid trying to enable AtomicOps on VFs; the PF setting applies to
     all VFs (Selvin Xavier)

  MSI:
   - Document that /sys/bus/pci/devices/.../irq contains the legacy INTx
     interrupt or the IRQ of the first MSI (not MSI-X) vector (Barry
     Song)

  VPD:
   - Add pci_read_vpd_any() and pci_write_vpd_any() to access anywhere
     in the possible VPD space; use these to simplify the cxgb3 driver
     (Heiner Kallweit)

  Peer-to-peer DMA:
   - Add (not subtract) the bus offset when calculating DMA address
     (Wang Lu)

  ASPM:
   - Re-enable LTR at Downstream Ports so they don't report Unsupported
     Requests when reset or hot-added devices send LTR messages
     (Mingchuang Qiao)

  Apple PCIe controller driver:
   - Add driver for Apple M1 PCIe controller (Alyssa Rosenzweig, Marc
     Zyngier)

  Cadence PCIe controller driver:
   - Return success when probe succeeds instead of falling into error
     path (Li Chen)

  HiSilicon Kirin PCIe controller driver:
   - Reorganize PHY logic and add support for external PHY drivers
     (Mauro Carvalho Chehab)
   - Support PERST# GPIOs for HiKey970 external PEX 8606 bridge (Mauro
     Carvalho Chehab)
   - Add Kirin 970 support (Mauro Carvalho Chehab)
   - Make driver removable (Mauro Carvalho Chehab)

  Intel VMD host bridge driver:
   - If IOMMU supports interrupt remapping, leave VMD MSI-X remapping
     enabled (Adrian Huang)
   - Number each controller so we can tell them apart in
     /proc/interrupts (Chunguang Xu)
   - Avoid building on UML because VMD depends on x86 bare metal APIs
     (Johannes Berg)

  Marvell Aardvark PCIe controller driver:
   - Define macros for PCI_EXP_DEVCTL_PAYLOAD_* (Pali Rohár)
   - Set Max Payload Size to 512 bytes per Marvell spec (Pali Rohár)
   - Downgrade PIO Response Status messages to debug level (Marek Behún)
   - Preserve CRS SV (Config Request Retry Software Visibility) bit in
     emulated Root Control register (Pali Rohár)
   - Fix issue in configuring reference clock (Pali Rohár)
   - Don't clear status bits for masked interrupts (Pali Rohár)
   - Don't mask unused interrupts (Pali Rohár)
   - Avoid code repetition in advk_pcie_rd_conf() (Marek Behún)
   - Retry config accesses on CRS response (Pali Rohár)
   - Simplify emulated Root Capabilities initialization (Pali Rohár)
   - Fix several link training issues (Pali Rohár)
   - Fix link-up checking via LTSSM (Pali Rohár)
   - Fix reporting of Data Link Layer Link Active (Pali Rohár)
   - Fix emulation of W1C bits (Marek Behún)
   - Fix MSI domain .alloc() method to return zero on success (Marek
     Behún)
   - Read entire 16-bit MSI vector in MSI handler, not just low 8 bits
     (Marek Behún)
   - Clear Root Port I/O Space, Memory Space, and Bus Master Enable bits
     at startup; PCI core will set those as necessary (Pali Rohár)
   - When operating as a Root Port, set class code to "PCI Bridge"
     instead of the default "Mass Storage Controller" (Pali Rohár)
   - Add emulation for PCI_BRIDGE_CTL_BUS_RESET since aardvark doesn't
     implement this per spec (Pali Rohár)
   - Add emulation of option ROM BAR since aardvark doesn't implement
     this per spec (Pali Rohár)

  MediaTek MT7621 PCIe controller driver:
   - Add MediaTek MT7621 PCIe host controller driver and DT binding
     (Sergio Paracuellos)

  Qualcomm PCIe controller driver:
   - Add SC8180x compatible string (Bjorn Andersson)
   - Add endpoint controller driver and DT binding (Manivannan
     Sadhasivam)
   - Restructure to use of_device_get_match_data() (Prasad Malisetty)
   - Add SC7280-specific pcie_1_pipe_clk_src handling (Prasad Malisetty)

  Renesas R-Car PCIe controller driver:
   - Remove unnecessary includes (Geert Uytterhoeven)

  Rockchip DesignWare PCIe controller driver:
   - Add DT binding (Simon Xue)

  Socionext UniPhier Pro5 controller driver:
   - Serialize INTx masking/unmasking (Kunihiko Hayashi)

  Synopsys DesignWare PCIe controller driver:
   - Run dwc .host_init() method before registering MSI interrupt
     handler so we can deal with pending interrupts left by bootloader
     (Bjorn Andersson)
   - Clean up Kconfig dependencies (Andy Shevchenko)
   - Export symbols to allow more modular drivers (Luca Ceresoli)

  TI DRA7xx PCIe controller driver:
   - Allow host and endpoint drivers to be modules (Luca Ceresoli)
   - Enable external clock if present (Luca Ceresoli)

  TI J721E PCIe driver:
   - Disable PHY when probe fails after initializing it (Christophe
     JAILLET)

  MicroSemi Switchtec management driver:
   - Return error to application when command execution fails because an
     out-of-band reset has cleared the device BARs, Memory Space Enable,
     etc (Kelvin Cao)
   - Fix MRPC error status handling issue (Kelvin Cao)
   - Mask out other bits when reading of management VEP instance ID
     (Kelvin Cao)
   - Return EOPNOTSUPP instead of ENOTSUPP from sysfs show functions
     (Kelvin Cao)
   - Add check of event support (Logan Gunthorpe)

  Miscellaneous:
   - Remove unused pci_pool wrappers, which have been replaced by
     dma_pool (Cai Huoqing)
   - Use 'unsigned int' instead of bare 'unsigned' (Krzysztof
     Wilczyński)
   - Use kstrtobool() directly, sans strtobool() wrapper (Krzysztof
     Wilczyński)
   - Fix some sscanf(), sprintf() format mismatches (Krzysztof
     Wilczyński)
   - Update PCI subsystem information in MAINTAINERS (Krzysztof
     Wilczyński)
   - Correct some misspellings (Krzysztof Wilczyński)"

* tag 'pci-v5.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (137 commits)
  PCI: Add ACS quirk for Pericom PI7C9X2G switches
  PCI: apple: Configure RID to SID mapper on device addition
  iommu/dart: Exclude MSI doorbell from PCIe device IOVA range
  PCI: apple: Implement MSI support
  PCI: apple: Add INTx and per-port interrupt support
  PCI: kirin: Allow removing the driver
  PCI: kirin: De-init the dwc driver
  PCI: kirin: Disable clkreq during poweroff sequence
  PCI: kirin: Move the power-off code to a common routine
  PCI: kirin: Add power_off support for Kirin 960 PHY
  PCI: kirin: Allow building it as a module
  PCI: kirin: Add MODULE_* macros
  PCI: kirin: Add Kirin 970 compatible
  PCI: kirin: Support PERST# GPIOs for HiKey970 external PEX 8606 bridge
  PCI: apple: Set up reference clocks when probing
  PCI: apple: Add initial hardware bring-up
  PCI: of: Allow matching of an interrupt-map local to a PCI device
  of/irq: Allow matching of an interrupt-map local to an interrupt controller
  irqdomain: Make of_phandle_args_to_fwspec() generally available
  PCI: Do not enable AtomicOps on VFs
  ...

1 files changed, 721 insertions, 0 deletions

diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
new file mode 100644
index 000000000000..7b17da2f9b3f
--- /dev/null
+++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
@@ -0,0 +1,721 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Qualcomm PCIe Endpoint controller driver
+ *
+ * Copyright (c) 2020, The Linux Foundation. All rights reserved.
+ * Author: Siddartha Mohanadoss <smohanad@codeaurora.org
+ *
+ * Copyright (c) 2021, Linaro Ltd.
+ * Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/mfd/syscon.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+
+#include "pcie-designware.h"
+
+/* PARF registers */
+#define PARF_SYS_CTRL				0x00
+#define PARF_DB_CTRL				0x10
+#define PARF_PM_CTRL				0x20
+#define PARF_MHI_BASE_ADDR_LOWER		0x178
+#define PARF_MHI_BASE_ADDR_UPPER		0x17c
+#define PARF_DEBUG_INT_EN			0x190
+#define PARF_AXI_MSTR_RD_HALT_NO_WRITES		0x1a4
+#define PARF_AXI_MSTR_WR_ADDR_HALT		0x1a8
+#define PARF_Q2A_FLUSH				0x1ac
+#define PARF_LTSSM				0x1b0
+#define PARF_CFG_BITS				0x210
+#define PARF_INT_ALL_STATUS			0x224
+#define PARF_INT_ALL_CLEAR			0x228
+#define PARF_INT_ALL_MASK			0x22c
+#define PARF_SLV_ADDR_MSB_CTRL			0x2c0
+#define PARF_DBI_BASE_ADDR			0x350
+#define PARF_DBI_BASE_ADDR_HI			0x354
+#define PARF_SLV_ADDR_SPACE_SIZE		0x358
+#define PARF_SLV_ADDR_SPACE_SIZE_HI		0x35c
+#define PARF_ATU_BASE_ADDR			0x634
+#define PARF_ATU_BASE_ADDR_HI			0x638
+#define PARF_SRIS_MODE				0x644
+#define PARF_DEVICE_TYPE			0x1000
+#define PARF_BDF_TO_SID_CFG			0x2c00
+
+/* PARF_INT_ALL_{STATUS/CLEAR/MASK} register fields */
+#define PARF_INT_ALL_LINK_DOWN			BIT(1)
+#define PARF_INT_ALL_BME			BIT(2)
+#define PARF_INT_ALL_PM_TURNOFF			BIT(3)
+#define PARF_INT_ALL_DEBUG			BIT(4)
+#define PARF_INT_ALL_LTR			BIT(5)
+#define PARF_INT_ALL_MHI_Q6			BIT(6)
+#define PARF_INT_ALL_MHI_A7			BIT(7)
+#define PARF_INT_ALL_DSTATE_CHANGE		BIT(8)
+#define PARF_INT_ALL_L1SUB_TIMEOUT		BIT(9)
+#define PARF_INT_ALL_MMIO_WRITE			BIT(10)
+#define PARF_INT_ALL_CFG_WRITE			BIT(11)
+#define PARF_INT_ALL_BRIDGE_FLUSH_N		BIT(12)
+#define PARF_INT_ALL_LINK_UP			BIT(13)
+#define PARF_INT_ALL_AER_LEGACY			BIT(14)
+#define PARF_INT_ALL_PLS_ERR			BIT(15)
+#define PARF_INT_ALL_PME_LEGACY			BIT(16)
+#define PARF_INT_ALL_PLS_PME			BIT(17)
+
+/* PARF_BDF_TO_SID_CFG register fields */
+#define PARF_BDF_TO_SID_BYPASS			BIT(0)
+
+/* PARF_DEBUG_INT_EN register fields */
+#define PARF_DEBUG_INT_PM_DSTATE_CHANGE		BIT(1)
+#define PARF_DEBUG_INT_CFG_BUS_MASTER_EN	BIT(2)
+#define PARF_DEBUG_INT_RADM_PM_TURNOFF		BIT(3)
+
+/* PARF_DEVICE_TYPE register fields */
+#define PARF_DEVICE_TYPE_EP			0x0
+
+/* PARF_PM_CTRL register fields */
+#define PARF_PM_CTRL_REQ_EXIT_L1		BIT(1)
+#define PARF_PM_CTRL_READY_ENTR_L23		BIT(2)
+#define PARF_PM_CTRL_REQ_NOT_ENTR_L1		BIT(5)
+
+/* PARF_AXI_MSTR_RD_HALT_NO_WRITES register fields */
+#define PARF_AXI_MSTR_RD_HALT_NO_WRITE_EN	BIT(0)
+
+/* PARF_AXI_MSTR_WR_ADDR_HALT register fields */
+#define PARF_AXI_MSTR_WR_ADDR_HALT_EN		BIT(31)
+
+/* PARF_Q2A_FLUSH register fields */
+#define PARF_Q2A_FLUSH_EN			BIT(16)
+
+/* PARF_SYS_CTRL register fields */
+#define PARF_SYS_CTRL_AUX_PWR_DET		BIT(4)
+#define PARF_SYS_CTRL_CORE_CLK_CGC_DIS		BIT(6)
+#define PARF_SYS_CTRL_SLV_DBI_WAKE_DISABLE	BIT(11)
+
+/* PARF_DB_CTRL register fields */
+#define PARF_DB_CTRL_INSR_DBNCR_BLOCK		BIT(0)
+#define PARF_DB_CTRL_RMVL_DBNCR_BLOCK		BIT(1)
+#define PARF_DB_CTRL_DBI_WKP_BLOCK		BIT(4)
+#define PARF_DB_CTRL_SLV_WKP_BLOCK		BIT(5)
+#define PARF_DB_CTRL_MST_WKP_BLOCK		BIT(6)
+
+/* PARF_CFG_BITS register fields */
+#define PARF_CFG_BITS_REQ_EXIT_L1SS_MSI_LTR_EN	BIT(1)
+
+/* ELBI registers */
+#define ELBI_SYS_STTS				0x08
+
+/* DBI registers */
+#define DBI_CON_STATUS				0x44
+
+/* DBI register fields */
+#define DBI_CON_STATUS_POWER_STATE_MASK		GENMASK(1, 0)
+
+#define XMLH_LINK_UP				0x400
+#define CORE_RESET_TIME_US_MIN			1000
+#define CORE_RESET_TIME_US_MAX			1005
+#define WAKE_DELAY_US				2000 /* 2 ms */
+
+#define to_pcie_ep(x)				dev_get_drvdata((x)->dev)
+
+enum qcom_pcie_ep_link_status {
+	QCOM_PCIE_EP_LINK_DISABLED,
+	QCOM_PCIE_EP_LINK_ENABLED,
+	QCOM_PCIE_EP_LINK_UP,
+	QCOM_PCIE_EP_LINK_DOWN,
+};
+
+static struct clk_bulk_data qcom_pcie_ep_clks[] = {
+	{ .id = "cfg" },
+	{ .id = "aux" },
+	{ .id = "bus_master" },
+	{ .id = "bus_slave" },
+	{ .id = "ref" },
+	{ .id = "sleep" },
+	{ .id = "slave_q2a" },
+};
+
+struct qcom_pcie_ep {
+	struct dw_pcie pci;
+
+	void __iomem *parf;
+	void __iomem *elbi;
+	struct regmap *perst_map;
+	struct resource *mmio_res;
+
+	struct reset_control *core_reset;
+	struct gpio_desc *reset;
+	struct gpio_desc *wake;
+	struct phy *phy;
+
+	u32 perst_en;
+	u32 perst_sep_en;
+
+	enum qcom_pcie_ep_link_status link_status;
+	int global_irq;
+	int perst_irq;
+};
+
+static int qcom_pcie_ep_core_reset(struct qcom_pcie_ep *pcie_ep)
+{
+	struct dw_pcie *pci = &pcie_ep->pci;
+	struct device *dev = pci->dev;
+	int ret;
+
+	ret = reset_control_assert(pcie_ep->core_reset);
+	if (ret) {
+		dev_err(dev, "Cannot assert core reset\n");
+		return ret;
+	}
+
+	usleep_range(CORE_RESET_TIME_US_MIN, CORE_RESET_TIME_US_MAX);
+
+	ret = reset_control_deassert(pcie_ep->core_reset);
+	if (ret) {
+		dev_err(dev, "Cannot de-assert core reset\n");
+		return ret;
+	}
+
+	usleep_range(CORE_RESET_TIME_US_MIN, CORE_RESET_TIME_US_MAX);
+
+	return 0;
+}
+
+/*
+ * Delatch PERST_EN and PERST_SEPARATION_ENABLE with TCSR to avoid
+ * device reset during host reboot and hibernation. The driver is
+ * expected to handle this situation.
+ */
+static void qcom_pcie_ep_configure_tcsr(struct qcom_pcie_ep *pcie_ep)
+{
+	regmap_write(pcie_ep->perst_map, pcie_ep->perst_en, 0);
+	regmap_write(pcie_ep->perst_map, pcie_ep->perst_sep_en, 0);
+}
+
+static int qcom_pcie_dw_link_up(struct dw_pcie *pci)
+{
+	struct qcom_pcie_ep *pcie_ep = to_pcie_ep(pci);
+	u32 reg;
+
+	reg = readl_relaxed(pcie_ep->elbi + ELBI_SYS_STTS);
+
+	return reg & XMLH_LINK_UP;
+}
+
+static int qcom_pcie_dw_start_link(struct dw_pcie *pci)
+{
+	struct qcom_pcie_ep *pcie_ep = to_pcie_ep(pci);
+
+	enable_irq(pcie_ep->perst_irq);
+
+	return 0;
+}
+
+static void qcom_pcie_dw_stop_link(struct dw_pcie *pci)
+{
+	struct qcom_pcie_ep *pcie_ep = to_pcie_ep(pci);
+
+	disable_irq(pcie_ep->perst_irq);
+}
+
+static int qcom_pcie_perst_deassert(struct dw_pcie *pci)
+{
+	struct qcom_pcie_ep *pcie_ep = to_pcie_ep(pci);
+	struct device *dev = pci->dev;
+	u32 val, offset;
+	int ret;
+
+	ret = clk_bulk_prepare_enable(ARRAY_SIZE(qcom_pcie_ep_clks),
+				      qcom_pcie_ep_clks);
+	if (ret)
+		return ret;
+
+	ret = qcom_pcie_ep_core_reset(pcie_ep);
+	if (ret)
+		goto err_disable_clk;
+
+	ret = phy_init(pcie_ep->phy);
+	if (ret)
+		goto err_disable_clk;
+
+	ret = phy_power_on(pcie_ep->phy);
+	if (ret)
+		goto err_phy_exit;
+
+	/* Assert WAKE# to RC to indicate device is ready */
+	gpiod_set_value_cansleep(pcie_ep->wake, 1);
+	usleep_range(WAKE_DELAY_US, WAKE_DELAY_US + 500);
+	gpiod_set_value_cansleep(pcie_ep->wake, 0);
+
+	qcom_pcie_ep_configure_tcsr(pcie_ep);
+
+	/* Disable BDF to SID mapping */
+	val = readl_relaxed(pcie_ep->parf + PARF_BDF_TO_SID_CFG);
+	val |= PARF_BDF_TO_SID_BYPASS;
+	writel_relaxed(val, pcie_ep->parf + PARF_BDF_TO_SID_CFG);
+
+	/* Enable debug IRQ */
+	val = readl_relaxed(pcie_ep->parf + PARF_DEBUG_INT_EN);
+	val |= PARF_DEBUG_INT_RADM_PM_TURNOFF |
+	       PARF_DEBUG_INT_CFG_BUS_MASTER_EN |
+	       PARF_DEBUG_INT_PM_DSTATE_CHANGE;
+	writel_relaxed(val, pcie_ep->parf + PARF_DEBUG_INT_EN);
+
+	/* Configure PCIe to endpoint mode */
+	writel_relaxed(PARF_DEVICE_TYPE_EP, pcie_ep->parf + PARF_DEVICE_TYPE);
+
+	/* Allow entering L1 state */
+	val = readl_relaxed(pcie_ep->parf + PARF_PM_CTRL);
+	val &= ~PARF_PM_CTRL_REQ_NOT_ENTR_L1;
+	writel_relaxed(val, pcie_ep->parf + PARF_PM_CTRL);
+
+	/* Read halts write */
+	val = readl_relaxed(pcie_ep->parf + PARF_AXI_MSTR_RD_HALT_NO_WRITES);
+	val &= ~PARF_AXI_MSTR_RD_HALT_NO_WRITE_EN;
+	writel_relaxed(val, pcie_ep->parf + PARF_AXI_MSTR_RD_HALT_NO_WRITES);
+
+	/* Write after write halt */
+	val = readl_relaxed(pcie_ep->parf + PARF_AXI_MSTR_WR_ADDR_HALT);
+	val |= PARF_AXI_MSTR_WR_ADDR_HALT_EN;
+	writel_relaxed(val, pcie_ep->parf + PARF_AXI_MSTR_WR_ADDR_HALT);
+
+	/* Q2A flush disable */
+	val = readl_relaxed(pcie_ep->parf + PARF_Q2A_FLUSH);
+	val &= ~PARF_Q2A_FLUSH_EN;
+	writel_relaxed(val, pcie_ep->parf + PARF_Q2A_FLUSH);
+
+	/* Disable DBI Wakeup, core clock CGC and enable AUX power */
+	val = readl_relaxed(pcie_ep->parf + PARF_SYS_CTRL);
+	val |= PARF_SYS_CTRL_SLV_DBI_WAKE_DISABLE |
+	       PARF_SYS_CTRL_CORE_CLK_CGC_DIS |
+	       PARF_SYS_CTRL_AUX_PWR_DET;
+	writel_relaxed(val, pcie_ep->parf + PARF_SYS_CTRL);
+
+	/* Disable the debouncers */
+	val = readl_relaxed(pcie_ep->parf + PARF_DB_CTRL);
+	val |= PARF_DB_CTRL_INSR_DBNCR_BLOCK | PARF_DB_CTRL_RMVL_DBNCR_BLOCK |
+	       PARF_DB_CTRL_DBI_WKP_BLOCK | PARF_DB_CTRL_SLV_WKP_BLOCK |
+	       PARF_DB_CTRL_MST_WKP_BLOCK;
+	writel_relaxed(val, pcie_ep->parf + PARF_DB_CTRL);
+
+	/* Request to exit from L1SS for MSI and LTR MSG */
+	val = readl_relaxed(pcie_ep->parf + PARF_CFG_BITS);
+	val |= PARF_CFG_BITS_REQ_EXIT_L1SS_MSI_LTR_EN;
+	writel_relaxed(val, pcie_ep->parf + PARF_CFG_BITS);
+
+	dw_pcie_dbi_ro_wr_en(pci);
+
+	/* Set the L0s Exit Latency to 2us-4us = 0x6 */
+	offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+	val = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP);
+	val &= ~PCI_EXP_LNKCAP_L0SEL;
+	val |= FIELD_PREP(PCI_EXP_LNKCAP_L0SEL, 0x6);
+	dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, val);
+
+	/* Set the L1 Exit Latency to be 32us-64 us = 0x6 */
+	offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+	val = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP);
+	val &= ~PCI_EXP_LNKCAP_L1EL;
+	val |= FIELD_PREP(PCI_EXP_LNKCAP_L1EL, 0x6);
+	dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, val);
+
+	dw_pcie_dbi_ro_wr_dis(pci);
+
+	writel_relaxed(0, pcie_ep->parf + PARF_INT_ALL_MASK);
+	val = PARF_INT_ALL_LINK_DOWN | PARF_INT_ALL_BME |
+	      PARF_INT_ALL_PM_TURNOFF | PARF_INT_ALL_DSTATE_CHANGE |
+	      PARF_INT_ALL_LINK_UP;
+	writel_relaxed(val, pcie_ep->parf + PARF_INT_ALL_MASK);
+
+	ret = dw_pcie_ep_init_complete(&pcie_ep->pci.ep);
+	if (ret) {
+		dev_err(dev, "Failed to complete initialization: %d\n", ret);
+		goto err_phy_power_off;
+	}
+
+	/*
+	 * The physical address of the MMIO region which is exposed as the BAR
+	 * should be written to MHI BASE registers.
+	 */
+	writel_relaxed(pcie_ep->mmio_res->start,
+		       pcie_ep->parf + PARF_MHI_BASE_ADDR_LOWER);
+	writel_relaxed(0, pcie_ep->parf + PARF_MHI_BASE_ADDR_UPPER);
+
+	dw_pcie_ep_init_notify(&pcie_ep->pci.ep);
+
+	/* Enable LTSSM */
+	val = readl_relaxed(pcie_ep->parf + PARF_LTSSM);
+	val |= BIT(8);
+	writel_relaxed(val, pcie_ep->parf + PARF_LTSSM);
+
+	return 0;
+
+err_phy_power_off:
+	phy_power_off(pcie_ep->phy);
+err_phy_exit:
+	phy_exit(pcie_ep->phy);
+err_disable_clk:
+	clk_bulk_disable_unprepare(ARRAY_SIZE(qcom_pcie_ep_clks),
+				   qcom_pcie_ep_clks);
+
+	return ret;
+}
+
+static void qcom_pcie_perst_assert(struct dw_pcie *pci)
+{
+	struct qcom_pcie_ep *pcie_ep = to_pcie_ep(pci);
+	struct device *dev = pci->dev;
+
+	if (pcie_ep->link_status == QCOM_PCIE_EP_LINK_DISABLED) {
+		dev_dbg(dev, "Link is already disabled\n");
+		return;
+	}
+
+	phy_power_off(pcie_ep->phy);
+	phy_exit(pcie_ep->phy);
+	clk_bulk_disable_unprepare(ARRAY_SIZE(qcom_pcie_ep_clks),
+				   qcom_pcie_ep_clks);
+	pcie_ep->link_status = QCOM_PCIE_EP_LINK_DISABLED;
+}
+
+/* Common DWC controller ops */
+static const struct dw_pcie_ops pci_ops = {
+	.link_up = qcom_pcie_dw_link_up,
+	.start_link = qcom_pcie_dw_start_link,
+	.stop_link = qcom_pcie_dw_stop_link,
+};
+
+static int qcom_pcie_ep_get_io_resources(struct platform_device *pdev,
+					 struct qcom_pcie_ep *pcie_ep)
+{
+	struct device *dev = &pdev->dev;
+	struct dw_pcie *pci = &pcie_ep->pci;
+	struct device_node *syscon;
+	struct resource *res;
+	int ret;
+
+	pcie_ep->parf = devm_platform_ioremap_resource_byname(pdev, "parf");
+	if (IS_ERR(pcie_ep->parf))
+		return PTR_ERR(pcie_ep->parf);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
+	pci->dbi_base = devm_pci_remap_cfg_resource(dev, res);
+	if (IS_ERR(pci->dbi_base))
+		return PTR_ERR(pci->dbi_base);
+	pci->dbi_base2 = pci->dbi_base;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "elbi");
+	pcie_ep->elbi = devm_pci_remap_cfg_resource(dev, res);
+	if (IS_ERR(pcie_ep->elbi))
+		return PTR_ERR(pcie_ep->elbi);
+
+	pcie_ep->mmio_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+							 "mmio");
+
+	syscon = of_parse_phandle(dev->of_node, "qcom,perst-regs", 0);
+	if (!syscon) {
+		dev_err(dev, "Failed to parse qcom,perst-regs\n");
+		return -EINVAL;
+	}
+
+	pcie_ep->perst_map = syscon_node_to_regmap(syscon);
+	of_node_put(syscon);
+	if (IS_ERR(pcie_ep->perst_map))
+		return PTR_ERR(pcie_ep->perst_map);
+
+	ret = of_property_read_u32_index(dev->of_node, "qcom,perst-regs",
+					 1, &pcie_ep->perst_en);
+	if (ret < 0) {
+		dev_err(dev, "No Perst Enable offset in syscon\n");
+		return ret;
+	}
+
+	ret = of_property_read_u32_index(dev->of_node, "qcom,perst-regs",
+					 2, &pcie_ep->perst_sep_en);
+	if (ret < 0) {
+		dev_err(dev, "No Perst Separation Enable offset in syscon\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int qcom_pcie_ep_get_resources(struct platform_device *pdev,
+				      struct qcom_pcie_ep *pcie_ep)
+{
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	ret = qcom_pcie_ep_get_io_resources(pdev, pcie_ep);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to get io resources %d\n", ret);
+		return ret;
+	}
+
+	ret = devm_clk_bulk_get(dev, ARRAY_SIZE(qcom_pcie_ep_clks),
+				qcom_pcie_ep_clks);
+	if (ret)
+		return ret;
+
+	pcie_ep->core_reset = devm_reset_control_get_exclusive(dev, "core");
+	if (IS_ERR(pcie_ep->core_reset))
+		return PTR_ERR(pcie_ep->core_reset);
+
+	pcie_ep->reset = devm_gpiod_get(dev, "reset", GPIOD_IN);
+	if (IS_ERR(pcie_ep->reset))
+		return PTR_ERR(pcie_ep->reset);
+
+	pcie_ep->wake = devm_gpiod_get_optional(dev, "wake", GPIOD_OUT_LOW);
+	if (IS_ERR(pcie_ep->wake))
+		return PTR_ERR(pcie_ep->wake);
+
+	pcie_ep->phy = devm_phy_optional_get(&pdev->dev, "pciephy");
+	if (IS_ERR(pcie_ep->phy))
+		ret = PTR_ERR(pcie_ep->phy);
+
+	return ret;
+}
+
+/* TODO: Notify clients about PCIe state change */
+static irqreturn_t qcom_pcie_ep_global_irq_thread(int irq, void *data)
+{
+	struct qcom_pcie_ep *pcie_ep = data;
+	struct dw_pcie *pci = &pcie_ep->pci;
+	struct device *dev = pci->dev;
+	u32 status = readl_relaxed(pcie_ep->parf + PARF_INT_ALL_STATUS);
+	u32 mask = readl_relaxed(pcie_ep->parf + PARF_INT_ALL_MASK);
+	u32 dstate, val;
+
+	writel_relaxed(status, pcie_ep->parf + PARF_INT_ALL_CLEAR);
+	status &= mask;
+
+	if (FIELD_GET(PARF_INT_ALL_LINK_DOWN, status)) {
+		dev_dbg(dev, "Received Linkdown event\n");
+		pcie_ep->link_status = QCOM_PCIE_EP_LINK_DOWN;
+	} else if (FIELD_GET(PARF_INT_ALL_BME, status)) {
+		dev_dbg(dev, "Received BME event. Link is enabled!\n");
+		pcie_ep->link_status = QCOM_PCIE_EP_LINK_ENABLED;
+	} else if (FIELD_GET(PARF_INT_ALL_PM_TURNOFF, status)) {
+		dev_dbg(dev, "Received PM Turn-off event! Entering L23\n");
+		val = readl_relaxed(pcie_ep->parf + PARF_PM_CTRL);
+		val |= PARF_PM_CTRL_READY_ENTR_L23;
+		writel_relaxed(val, pcie_ep->parf + PARF_PM_CTRL);
+	} else if (FIELD_GET(PARF_INT_ALL_DSTATE_CHANGE, status)) {
+		dstate = dw_pcie_readl_dbi(pci, DBI_CON_STATUS) &
+					   DBI_CON_STATUS_POWER_STATE_MASK;
+		dev_dbg(dev, "Received D%d state event\n", dstate);
+		if (dstate == 3) {
+			val = readl_relaxed(pcie_ep->parf + PARF_PM_CTRL);
+			val |= PARF_PM_CTRL_REQ_EXIT_L1;
+			writel_relaxed(val, pcie_ep->parf + PARF_PM_CTRL);
+		}
+	} else if (FIELD_GET(PARF_INT_ALL_LINK_UP, status)) {
+		dev_dbg(dev, "Received Linkup event. Enumeration complete!\n");
+		dw_pcie_ep_linkup(&pci->ep);
+		pcie_ep->link_status = QCOM_PCIE_EP_LINK_UP;
+	} else {
+		dev_dbg(dev, "Received unknown event: %d\n", status);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t qcom_pcie_ep_perst_irq_thread(int irq, void *data)
+{
+	struct qcom_pcie_ep *pcie_ep = data;
+	struct dw_pcie *pci = &pcie_ep->pci;
+	struct device *dev = pci->dev;
+	u32 perst;
+
+	perst = gpiod_get_value(pcie_ep->reset);
+	if (perst) {
+		dev_dbg(dev, "PERST asserted by host. Shutting down the PCIe link!\n");
+		qcom_pcie_perst_assert(pci);
+	} else {
+		dev_dbg(dev, "PERST de-asserted by host. Starting link training!\n");
+		qcom_pcie_perst_deassert(pci);
+	}
+
+	irq_set_irq_type(gpiod_to_irq(pcie_ep->reset),
+			 (perst ? IRQF_TRIGGER_HIGH : IRQF_TRIGGER_LOW));
+
+	return IRQ_HANDLED;
+}
+
+static int qcom_pcie_ep_enable_irq_resources(struct platform_device *pdev,
+					     struct qcom_pcie_ep *pcie_ep)
+{
+	int irq, ret;
+
+	irq = platform_get_irq_byname(pdev, "global");
+	if (irq < 0) {
+		dev_err(&pdev->dev, "Failed to get Global IRQ\n");
+		return irq;
+	}
+
+	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+					qcom_pcie_ep_global_irq_thread,
+					IRQF_ONESHOT,
+					"global_irq", pcie_ep);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to request Global IRQ\n");
+		return ret;
+	}
+
+	pcie_ep->perst_irq = gpiod_to_irq(pcie_ep->reset);
+	irq_set_status_flags(pcie_ep->perst_irq, IRQ_NOAUTOEN);
+	ret = devm_request_threaded_irq(&pdev->dev, pcie_ep->perst_irq, NULL,
+					qcom_pcie_ep_perst_irq_thread,
+					IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
+					"perst_irq", pcie_ep);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to request PERST IRQ\n");
+		disable_irq(irq);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int qcom_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
+				  enum pci_epc_irq_type type, u16 interrupt_num)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+
+	switch (type) {
+	case PCI_EPC_IRQ_LEGACY:
+		return dw_pcie_ep_raise_legacy_irq(ep, func_no);
+	case PCI_EPC_IRQ_MSI:
+		return dw_pcie_ep_raise_msi_irq(ep, func_no, interrupt_num);
+	default:
+		dev_err(pci->dev, "Unknown IRQ type\n");
+		return -EINVAL;
+	}
+}
+
+static const struct pci_epc_features qcom_pcie_epc_features = {
+	.linkup_notifier = true,
+	.core_init_notifier = true,
+	.msi_capable = true,
+	.msix_capable = false,
+};
+
+static const struct pci_epc_features *
+qcom_pcie_epc_get_features(struct dw_pcie_ep *pci_ep)
+{
+	return &qcom_pcie_epc_features;
+}
+
+static void qcom_pcie_ep_init(struct dw_pcie_ep *ep)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+	enum pci_barno bar;
+
+	for (bar = BAR_0; bar <= BAR_5; bar++)
+		dw_pcie_ep_reset_bar(pci, bar);
+}
+
+static struct dw_pcie_ep_ops pci_ep_ops = {
+	.ep_init = qcom_pcie_ep_init,
+	.raise_irq = qcom_pcie_ep_raise_irq,
+	.get_features = qcom_pcie_epc_get_features,
+};
+
+static int qcom_pcie_ep_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct qcom_pcie_ep *pcie_ep;
+	int ret;
+
+	pcie_ep = devm_kzalloc(dev, sizeof(*pcie_ep), GFP_KERNEL);
+	if (!pcie_ep)
+		return -ENOMEM;
+
+	pcie_ep->pci.dev = dev;
+	pcie_ep->pci.ops = &pci_ops;
+	pcie_ep->pci.ep.ops = &pci_ep_ops;
+	platform_set_drvdata(pdev, pcie_ep);
+
+	ret = qcom_pcie_ep_get_resources(pdev, pcie_ep);
+	if (ret)
+		return ret;
+
+	ret = clk_bulk_prepare_enable(ARRAY_SIZE(qcom_pcie_ep_clks),
+				      qcom_pcie_ep_clks);
+	if (ret)
+		return ret;
+
+	ret = qcom_pcie_ep_core_reset(pcie_ep);
+	if (ret)
+		goto err_disable_clk;
+
+	ret = phy_init(pcie_ep->phy);
+	if (ret)
+		goto err_disable_clk;
+
+	/* PHY needs to be powered on for dw_pcie_ep_init() */
+	ret = phy_power_on(pcie_ep->phy);
+	if (ret)
+		goto err_phy_exit;
+
+	ret = dw_pcie_ep_init(&pcie_ep->pci.ep);
+	if (ret) {
+		dev_err(dev, "Failed to initialize endpoint: %d\n", ret);
+		goto err_phy_power_off;
+	}
+
+	ret = qcom_pcie_ep_enable_irq_resources(pdev, pcie_ep);
+	if (ret)
+		goto err_phy_power_off;
+
+	return 0;
+
+err_phy_power_off:
+	phy_power_off(pcie_ep->phy);
+err_phy_exit:
+	phy_exit(pcie_ep->phy);
+err_disable_clk:
+	clk_bulk_disable_unprepare(ARRAY_SIZE(qcom_pcie_ep_clks),
+				   qcom_pcie_ep_clks);
+
+	return ret;
+}
+
+static int qcom_pcie_ep_remove(struct platform_device *pdev)
+{
+	struct qcom_pcie_ep *pcie_ep = platform_get_drvdata(pdev);
+
+	if (pcie_ep->link_status == QCOM_PCIE_EP_LINK_DISABLED)
+		return 0;
+
+	phy_power_off(pcie_ep->phy);
+	phy_exit(pcie_ep->phy);
+	clk_bulk_disable_unprepare(ARRAY_SIZE(qcom_pcie_ep_clks),
+				   qcom_pcie_ep_clks);
+
+	return 0;
+}
+
+static const struct of_device_id qcom_pcie_ep_match[] = {
+	{ .compatible = "qcom,sdx55-pcie-ep", },
+	{ }
+};
+
+static struct platform_driver qcom_pcie_ep_driver = {
+	.probe	= qcom_pcie_ep_probe,
+	.remove = qcom_pcie_ep_remove,
+	.driver	= {
+		.name = "qcom-pcie-ep",
+		.of_match_table	= qcom_pcie_ep_match,
+	},
+};
+builtin_platform_driver(qcom_pcie_ep_driver);
+
+MODULE_AUTHOR("Siddartha Mohanadoss <smohanad@codeaurora.org>");
+MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
+MODULE_DESCRIPTION("Qualcomm PCIe Endpoint controller driver");
+MODULE_LICENSE("GPL v2");